Means for protecting the rod of a hydraulic lift jack from damage by the lift chain

ABSTRACT

A protective band of flexible material is connected at its opposite ends to the lift chain of a lift truck and passes over the upper end of the rod of the lift jack beneath the chain roller. The protective band is in a protecting relation to the rod of the jack at both sides thereof and absorbs slapping impact of the chain during operation of the truck.

United States Patent [1 1 Garnett I v MEANS FOR PROTECTING THE ROD OF A HYDRAULIC LIFT JACK FROM DAMAGE BY THE LIFT CHAIN [75] Inventor: Donald P. Garnett, l-lomewood, 111.

[73] Assignee: Allis-Chalmers Corporation,

Milwaukee, Wis.

[22] Filed: Mar. 11, 1974 [21] Appl. No.: 450,010

[52] US. Cl. 254/4 C, 187/9 E, 254/93 R [51] Int. Cl B60p l/14, B60p l/22,-B66f 3/24 [58] Field of Search 254/2 R, 2 B, 2 C, 4 R,

254/4 B, 4 C, 93 R, 93 L; 187/9 R, 9 E

[56] References Cited UNITED STATES PATENTS 2,419,938 5/1947 Abbe 189/9 E Dec. 17, 1974 10/1959 Southerwick 254/2 B 4/1961 Quayle 187/9 E Primary EXaminrOthell M. Simpson Attorney, Agent, or Firm-Char1es L. Schwab 57 ABSTRACT- A' protective band of flexible material is connected at its opposite ends to the lift chain of a lift'truck and passes over the upper end of the rod of the lift jack beneath the chain roller. The protective band is in a protecting relation to the rod of the jack at both sides thereof and absorbs slapping impact of the chain during operation of the truck.

5 Claims, 5 Drawing Figures PATENTED 3531 71974 3, 854, 69 9 MEANS FOR PROTECTING THE ROD-OF A HYDRAULIC LIFT JACK FROM DAMAGE BY THE LIFT CHAIN BACKGROUND OF THE INVENTION The rods of the lift jacks of lift trucks are subject to damage by the lift chain slapping thereagainst. Heretofore, a rigid member has been secured to the upper end of the rod so as to extend downwardly along the back of the rod to protect it from any slapping action of the chain. This method has not proven entirely satisfactory in reliability and the front side of the rod was not protected.

BRIEF DESCRIPTION OF THE INVENTION A flexible band of suitable material such as nylon or the like is connected at its opposite ends to the lift chain so as to be disposed between the chain and the rod of the lift jack at all times during extension and contraction of the rod. The flexible band passes beneath the roller on the upper end of the rod, thus avoiding thecrushing and wearing action that would otherwise occur if the band were run with the chain over the roller.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is illustrated in the attached drawings in which:

FIG. 1 is a side view of the lift truck incorporating the present invention;

FIG. 2 is a front view of the truck shown in FIG. 1;

FIG. 3 is an enlarged side view of part of the truck shown in FIG. 1 and showing the present invention with the lift carriage in alowered position;

FIG. 4 is a view similar to FIG. 3 but showing the lift rod extended from the cylinder structure of the jack so as to raise the carriage; and

FIG. "5 is a front view of the structure shown in FIG. 4 with some parts broken away.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to FIGS. 1 and 2, the invention is incorporated in a riding type lift truck having a main frame 11 supported at its rear end by a pair of steerable wheels 13 and at its front end by a pair of drive wheels 14. A suitable steering wheel 16 is provided at the operators station 17 which is within the confines of an overhead guard 18. A mast or mast structure 19 includes a pair of outer uprights 20, 21 which are interconnected at their bottom by a cross'member l5 and are connected to the truck main frame 11 in a conventional manner. A lift carriage 22 is mounted by rollers (not shown) on an inner pair of channel section uprights'23, 24 of the lift truck mast 19. The carriage 22'supports a pair of lift forks 26 which are adapted to receive and carry palletized loads and the like. The carriage 22 is raised and lowered on the mast by a hydraulic lift jack assembly 27 which includes a central jack 28 and a pair of chain carrying lift jacks 29, 30 disposed on opposite lateral sides of the central jack 28. The cylinder structures 31, 32 of the lift jacks 29, 30 are rigidly secured to the cylinder component of the central jack 28 as by welding same to spacer blocks 9 positioned therebetween. The cylinder structures 31, 32, 35 are secured at their lower ends to a cross member interconnecting the inner uprights 23, 24. The rod of the central jack 28 extends through an opening in the cross member 40 and is secured to the cross member 15.

As shown in FIGS. 3, 4 and 5, the lift jack 30 includes a piston rod 33 which rotatably supports a roller 34 at the upper end thereof on a horizontal pivot axis 36. A lift chain 37 is reeved or trained over the roller 34 and has its opposite ends secured, respectively, to the cylinder structure 32 and to the carriage 22. One end of the chain 37 is connected to an eye bolt 39 which is fixedly secured to the bracket 38 by a pair of nuts 41. The other end of the chain 37 is secured to a bracket 46 at the rear of the carriage 22 by a suitable pin 47. The upper end of the rod 33 is U-shaped and includes a pair of upstanding brackets 51, 52with aligned drilled holes 54, 56 supporting a shaft 53 for the roller 34.

In order to protect the rod 33 from damage by the slapping action of the chain 37 when the rod is extended from the cylinder structure 32, a flexible protective band 61 is secured at its opposite ends to the-lift chain 37 by releasable fastening means 62. The protective band 61 is disposed between the chain 37 and the rod 33 at diametrically opposite sides of the. latter and passes between the upstanding brackets 51, 52 and beneath the roller 34. Thus the protective band 61 does not pass over the top of the roller. 34 with the chain 37,

where it would be crushed between the chain 37 and the roller 34. The upstanding brackets 51, 52 serve as guide means to maintain the band 61 in juxtaposed relation to said chain at diametrically opposite sides of the rod 33.

The protective band 61, which may be made of nylon I are secured to the chain by releasable fastening means 62 whereby the flexible band 61 can be replaced, should it become excessively worn, without removing the lift chain 37. Each of the fastening means 62includes a bolt 63 having an enlarged head 64, a washer 66 and a nut 67.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a lift truck having a mast structure, a carriage I.

reciprocably mounted on said mast structure for vertical movement, means for raising and lowering said carriage on said mast structure including a lift jack with a cylinder structure supported on said truck and a rod having an upper end extending from thetop of said cylinder structure, a roller carried on said upper end of said rod for rotation about a horizontal axis and a chain trained over said roller and having one end-secured to one of said structures and its other end secured to said carriage, the improvement comprising a flexible protective band passing beneath said roller and between the latter and said upper end of said rod and having-its opposite ends secured to said chain, said band being disposed between said chain and said lift jack at diametrically opposite sides of the latter and operable to prevent said chain from 4 I said roller is rotatably mounted on and between said flanges, and said protective band passes between said flanges and beneath said roller.

5. The structure of claim 1 wherein said band is secured to said chain by releasable fastening means permitting replacement of said band without removal of said chain. a 

1. In a lift truck having a mast structure, a carriage reciprocably mounted on said mast structure for vertical movement, means for raising and lowering said carriage on said mast structure including a lift jack with a cylinder structure supported on said truck and a rod having an upper end extending from the top of said cylinder structure, a roller carried on said upper end of said rod for rotation about a horizontal axis and a chain trained over said roller and having one end secured to one of said structures and its other end secured to said carriage, the improvement comprising: a flexible protective band passing beneath said roller and between the latter and said upper end of said rod and having its opposite ends secured to said chain, said band being disposed between said chain and said lift jack at diametrically opposite sides of the latter and operable to prevent said chain from slapping said rod when the latter is extended from said cylinder structure.
 2. The structure of claim 1 wherein said protective band is at least as wide as said chain.
 3. The structure of claim 1 wherein said band is at least as long as the operating stroke of said jack.
 4. The structure of claim 1 wherein said upper end of said rod includes a pair of spaced upstanding flanges, said roller is rotatably mounted on and between said flanges, and said protective band passes between said flanges and beneath said roller.
 5. The structure of claim 1 wherein said band is secured to said chain by releasable fastening means permitting replacement of said band without removal of said chain. 